The purpose of this research study is to determine if changes in infrared thermography measurements (a device to measure body temperatures) can be correlated with changes in any of these short-term measures. The ultimate goal of this type of research is to determine if infrared thermography can be used as a short-term predictor of weight loss that occurs over a much longer period of time. The two drugs, ephedrine sulfate and sibutramine, are FDA approved and have been studied for weight loss. These two drugs will be given to test their immediate effects on the measurements taken during this study. There is no evidence to suggest that single doses of these drugs will result in any weight loss, however changes in resting metabolic rate, biological markers, and body temperature are anticipated.